Questioning Forensics

Questioning forensics

Questioning forensics

 

While the significance of forensic evidence in criminal trials has risen, questions about validity of forensic analyses also arise. A recent article in the Journal of Applied Research in Memory and Cognition offers a psychological study on various factors that may influence the findings of a forensic science examiner. “The Forensic Confirmation Bias: Problems, Perspectives, and Proposed Solutions,” was written by Saul Kassin and Jeff Kukucka of John Jay College of Criminal Justice (New York City), and Itiel Dror of University College London (United Kingdom).

In the following paragraph, the authors highlight problems with forensics (citations omitted).

Popular TV programs, such as CSI, communicate a false belief in the powers of forensic science, a problem that can be exacerbated when forensic experts overstate the strength of the evidence. Such occurrences are common when you consider the following: (1) Across many domains, experts are often overconfident in their abilities; (2) the courts, for the most part, have blindly accepted forensic science evidence without much scrutiny; (3) errors are often not apparent in the forensic sciences because ground truth is often not known as a matter of certainty; (4) many forensic examiners work for police and appear in court as advocates for the prosecution; and (5) many forensic examiners consider themselves objective and immune to bias. As stated by the Chair of the Fingerprint Society: “Any fingerprint examiner who comes to a decision on identification and is swayed either way in that decision making process under the influence of stories and gory images is either totally incapable of performing the noble tasks expected of him/her or is so immature he/she should seek employment at Disneyland.”

If you plan to explore a possible forensics flaw in your story, then you may want to peruse the article, which is available at the Science Direct website.

 

NIBIN

Case comparison

Photo shows two test-fired cartridge cases from the same firearm compared side-by-side with a comparison microscope. Source: Stephen G. Bunch et al., “Is a Match Really a Match? A Primer on the Procedures and Validity of Firearm and Toolmark Identification,” Forensic Science Communications 11(3) (July 2009).

 

Fourteen years ago the ATF (today, called the Bureau of Alcohol, Tobacco, Firearms and Explosives) set up the National Integrated Ballistic Information Network (NIBIN). US partners of this network use Integrated Ballistic Identification Systems (IBIS) to obtain digital images of marks on fired cartridge cases and bullets. These cases and bullets are either recovered from a crime scene or from a test firing of a suspect weapon. The images are electronically compared with stored NIBIN entries. On TV shows, an electronic match – a hit – often ends the investigation. In real life, a high-confidence electronic match means that a firearms examiner compares original evidence with a microscope to confirm the match. So far, NIBIN partners have confirmed more than 50,000 NIBIN hits.

Last month, KVOA’s Lupita Murillo in Tucson reported a practical problem with NIBIN analysis. Although an electronic comparison may only require hours, somebody has to acquire and upload digital images into the network. The Tucson Police Crime Lab had 1,200 backlogged cases that needed to be entered into the system.

 

DNA – Fast

DNA

 

Those multitasking, gun-toting TV CSIs perform DNA tests at record-breaking speeds. After all, they need to solve a crime in 44 minutes (allowing for commercials). The speed of real DNA analysis is catching up.

IntegenX® (Pleasanton, CA) has introduced its RapidHIT 200, which enables investigators to run a DNA test in a quick 90 minutes. The portable RapidHIT 200 is about the size of a small copy machine, and it analyzes DNA in a cheek swab. The device will allow law enforcement officers to quickly identify genuine suspects and eliminate people unrelated to the criminal activity.

“You’re going to see it in the field more,” said Jay Henry, laboratory director for the Bureau of Forensic Services (Salt Lake City). “The crime lab will be the crime scene. You can find out a lot more at the crime scene itself.”

The IntegenX website provides details about this technology, including a link to a recent Evidence Technology Magazine article highlighting RapidHIT.